bt8960 Mindspeed Technologies, bt8960 Datasheet - Page 58

• Manufacturer Part Number: bt8960
• Description: Bt8960, Single-chip 2b1q Transceiver
• Manufacturer: Mindspeed Technologies

48
3.0 Registers
3.1 Conventions
3.2.8 0x07—Receive Phase Select Register (receive_phase_select)
rphs[3:0]
3.2.9 0x08—Linear Echo Canceller Modes Register (linear_ec_modes)
enable_dc_tap
adapt_coefficents
zero_coefficients
Interface
mode
[1:0]
00
01
10
11
7
7
–
–
Parallel Master —Parallel quat transfer
synchronized to QCLK out.
Parallel Slave—Parallel quat transfer
synchronized to separate TBCLK and
RBCLK inputs.
Serial, Magnitude First. Serial quat
transfer synchronized to BCLK out;
magnitude-bit first followed by sign bit.
Serial, Sign First. Serial quat transfer
synchronized to BCLK out; sign-bit first
followed by magnitude bit.
Receive Phase Select—Read/write binary field that defines the relative phase relationship
between QCLK and the sampling point of the ADC. The rising edges of QCLK corresponds to
the ADC sampling point when rphs = 0000. Each binary increment of rphs represents a one-
sixteenth QCLK period delay in the sampling point relative to QCLK.
Enable DC Tap—Read/write control bit which, when set, forces a constant +1 value into the
last data tap of the Linear Echo Canceller (LEC). This condition enables cancellation of any
residual DC offset present at the input to the LEC. When cleared, the last data tap operates nor-
mally, as the oldest transmit data sample.
Adapt Coefficients—Read/write control bit which enables coefficient adaptation when set; dis-
ables/freezes adaptation when cleared. Coefficient values are preserved when adaptation is dis-
abled.
Zero Coefficients—Read/write control bit that continuously zeros all coefficients when set;
allows normal coefficient updates, if enabled, when cleared. This behavior differs slightly from
the similar function (zero_coefficients) of the FFE and EP filters.
6
6
–
–
enable_dc_tap
Mode
5
–
5
coefficients
adapt_
4
–
4
N8960DSB
Not
used
TBCLK
Not
used
Not
used
91
zero_coefficients
rphs[3]
3
3
Not
used
RBCLK
Not
used
Not
used
90
zero_output
RQ[1]
RDAT
RDAT
RQ[1]
rphs[2]
Pin Functions
88
2
2
Single-Chip 2B1Q Transceiver
RQ[0]
RQ[0]
BCLK
BCLK
89
adapt_gain[1]
rphs[1]
1
1
TQ[1]
TQ[1]
TDAT
TDAT
85
adapt_gain[0]
rphs[0]
Bt8960
TQ[0]
Not
used
Not
used
TQ[0]
0
0
86